《Table 1Crosslinking degree for t PA copolymer and t PA/HEA-f-MWCNT composites》

《Table 1Crosslinking degree for t PA copolymer and t PA/HEA-f-MWCNT composites》   提示:宽带有限、当前游客访问压缩模式
本系列图表出处文件名:随高清版一同展现
《Effect of Electron Beam Irradiation on Thermal and Mechanical Properties of Polyamide Copolymer/Multiwall Carbon Nanotube Composites》


  1. 获取 高清版本忘记账户?点击这里登录
  1. 下载图表忘记账户?点击这里登录

The change in gel content can represent the variation in the crosslinking degree of tPA copolymer and its composites[24].Here,addition of 2 parts per hundred(phr)HEA-f-MWCNT into tPA copolymer is referred to as tPA/HEA-f-MWCNT(100/2)composite.The relationship between the gel content of tPA/HEA-f-MWCNT composites and the e-beam irradiation dose is shown in Fig.2.The gel content of tPA copolymer before e-beam irradiation is 13%.It changes slightly with the increase of the irradiation dose,and reaches a maximum of 23%at 80 kGy.After that,the gel content gradually decreases with the increase of the irradiation dose.This phenomenon indicates that e-beam irradiation cannot efficiently initiate crosslinking reaction in the molecular chains of pristine t PA copolymer.However,the gel contents of tPA/HEA-f-MWCNT(100/1,100/2)composites are higher than that of t PA copolymer.With the increase of the irradiation dose from 80 to 160 kGy,the gel content of tPA/HEA-f-MWCNT(100/2)composite increases gradually,reaches a maximum value of 40%at 160 kGy,and subsequently drops to 16%at 200 kGy.The gel content of tPA/HEA-f-MWCNT(100/1)composite increases sharply to about 43%at 160 k Gy,and subsequently,it is similar to that of tPA/HEA-f-MWCNT(100/2)composite.Compared with tPA/HEA-f-MWCNT(100/1)composite,tPA/HEA-f-MWCNT(100/2)composite gets a higher gel content at a low irradiation dose.Besides,it can be seen from Table 1 that the value of Gs/Gxfor tPA copolymer is 3.44,while this value turns to 2.36 for tPA/HEA-f-MWCNT(100/1)composite,and 2.02 for tPA/HEA-f-MWCNT(100/2)composite.As an effective crosslinking co-agent,HEA-f-MWCNT has played a very important role in accelerating the process of crosslinking through the generation of free radicals during irradiation by e-beam.Free radicals can not only promote the crosslinking reactions between the molecular chains,but also cause the degradation of a polymer.The degradation degree is small at a low irradiation dose,and the change of gel content is mainly affected by the crosslinking degree.However,the degradation degree is gradually increased with further increasing the irradiation dose,and thus the gel content is reduced.The effect of HEA-f-MWCNT on the gel content has been removed.